An electrophysiology data acquisition system is used in biological experiments to monitor and record electrical signals from a subject (e.g., a cell) under test. In such experiments, a researcher may use an experimental rig in which the subject is disposed. The researcher may also secure an electrode to the subject, for example, using a patch clamp technique, and then analyze the electrical signals detected by the electrode. The electrical signals from the subject may be low-level signals generated by a high-impedance signal source. As a result, such signals may be especially susceptible to electromagnetic interference (EMI) from radiated and conducted emissions of equipment connected to a mains power source. Such EMI may distort the signal of interest and appear as a “noise” or “hum” waveform added to such signal. Further, such noise may be periodic in accordance with the frequency of the electrical current generated by the mains power source. Such frequency is typically 50 hz or 60 hz and low harmonics thereof.
The researcher may use power line conditioners, Faraday cages, avoidance of “ground loops”, and the like to isolate the experimental rig from environmental noise sources. Nevertheless, even when great care is taken, EMI may still be introduced in the electrical signal transmitted from the electrode to a data acquisition system. Further, if such electrical signal is affected by EMI at a time in the life cycle of the subject of interest to the researcher, the efforts of the researcher to prepare and isolate the subject may be for naught. Such EMI may result in lost time troubleshooting the experimental apparatus or, worse, in missing the time-window in which live cells must be measured and an irrecoverable loss of the cells.